James huber



J. HUBER.

FIRING GEAR FOB DEPTH MINES.

APPLlcAmN man FEB. 28, 191e.

Patented Sept. 2, l19'19,

UNITED STATE-s PATENT oFFioE.

JAMES HUBER, 0F PHILADELPHIA, PENNSYLVANIA, ASSIGNOR T0 VICKERS LIMITED,

y 0F WESTMINSTER, LONDON, ENGLAND.

FIRING-GEAR FOR DEPTH-MINES.

, Specification of Letters Patent.

Patented Sept. 2, 1919.

Application led February 28, 1 918. Serial No. 219,637.

State of Pennsylvania, have invented certain new and useful Improvementsin F iring-Gears for Depth-Mines; and I do hereby declare the followingto be a' full, clear, and exact description of the invention,such

as will enable others skilled in the art to which it appertains to makeand use the same. I l This invention relates to a firing gear for depthmines and particularly to means for preventing the actuation of thedetonator before the mine reaches a predetermined depth.

During the launching of a depth mine, when the mine is thrown from aship, 1t often occurs that the firing gear strikes the water first, sothat it is subjected to very great pressure, in fact to suchpressure,that unless some means is provided for absorbing the pressurethe detonator wouldv be prematurely moved Furthermore, when one mineexplodes adjacent to another, the pressure increases to such `an extentthatl unless such an absorbing means is provlded, the detonator will beactuated. Of course, the disadvantage here lies inthe fact that when onemine is planted and reaches the proper depth for firing it will causethe explosion of a subsequently planted mine which, however, has notreached the proper depth. It is, therefore, an object of the presentinvention to provide means for absorbing the temporary increase inpressure occurring during the planting ot the mine, or caused by anadjacent explosion, so that the detonator will not be actuated until themine reaches the proper depth for explosion. l

In the drawing I have illustrated an embodiment of the invention, theligure being the section of the firing gear and. of a portion of themine.

The mine is of the usual form and includes an ignition charge case 1, amain charge case?, and a chamber 3 which'permits the expansionv of thegases generated by the untimely explosion of the detonator, so that theignition and main charges will not be exploded by such a premature or-untimely explosion of the detonator.

A lcasting 4 is attached tothe upper portion of the mine above thechamber 3 by means of screw threads 5, the joint being made by asuitable gasket 6. Mounted onV and depending'from this casting 4 is adetonator guide tube .7 in which a detonator and detonatoractuating'mechanism, similar to that illustrated and described in my'copendlng application, Serial No. 216,817, ledFebruary 12, 1918, ismounted. As described in saidapplication, the detonator is slidablewithin they tube 7 and is 'acuated by means of a spring 8, which latteris compressed by the downward movement of the piston 9. This downwardmovement of the piston is caused by the pressure of the water whichoperates against the piston when the mine reaches a predetermined depth.The casting 4 is provided with an axial bore 10,

4which at its lower end is reduced as at 11,

forming an annular flange l2, and is at its upper end enlarged as at13.v A cap 14 is attached to the upper end of the casting 4 by means ofscrew threads 15, or inv any other suitable manner. This cap is providedwith a plurality of openings 16 through which the water may pass tothebore 10 andI consequently to the piston9. A plu- I rahty of dlaphragms17 are mountedv n t spaced relation to each other in the bore 10, thediaphragms being maintained i'n their spaced relation by means ofspacing collars i 18. These diaphragms 17 are made of 'fran-1 giblematerial and are of such thickness that they will successively. breakupon the' application of a predetermined water pressure.l Thediaphragmsare all varranged to break at the same pressure, so that when thepressure is applied tothe uppermostof the -diaphragms,'it willprogressively rupture the diaphragms in ia very short time.`

A compression washer 19 rests upon the uppermost of the spacing collars18 vand ,is

forced downward against the same by the lower end of the cap 14, sovthat the diaphragms will all be clamped between thel collars and thusproperly held in. position.

A wire gauze 20 is clamped between. the lower end of this cap 14 andtherwashe'r 19,v

and extends across the opening inithe washer, so that the water passingthrough the openings 16 may pass directly into the bore 10, pressure isreached, to thepiston 9;

and consequently when the proper The openings 1G are arranged adjacentto the lower end of the cap 1l and the cap is provided with a chamber 21above the openings in which chamber a piston 22 1s operable, the pistonnormally being located )ust above the openings 16 and being held in suchposition by a bushing 23, against which 1t rests, which bushing isprovided with openings alining with the openings 1G in the cap 1st.Interposed between the plston Q2 and the wall of the chamber 21 is aspring 2-1, against which the piston'must operate in order to moveupwardly.

If the mine properly reaches the depth at which it is constructed toexplode, without encountering any sudden and temporary shocks, the waterwill pass through the gauze 20 and successively rupture the dlaphragms17 until it has direct access to the piston 9, at which time it willoperate the piston, which in turn will actuate the detonator.If,however,the Water pressure s uddenly and temporarily increases at anytime during the descent of the mine, or during the planting of the same,naturally the pressure of the Water within the cap 14 will increase. Ifthe piston 22 were stationary, this increase of pressure would cause theWater to rupture the diaphragms 17, but inasmuch as the piston 22 isonly held in its lowermost position by the spring 24, the piston iscaused to move upwardly against the action of the spring by the increaseof pressure, so that the effect fof the increase is practicallydestroyed. Furthermore, the wire gauze further destroys the effect ofthis increased pressure, so that normally, the diaphragms 17 Will not beruptured. Should the pressure increase to such an extent that the entireexcess pressure will not be destroyed by the action of the piston 22 andthe gauze 20, it is possible'that the uppermost of the diaphragms. 17will be ruptured, or even that a number of these diaphragms will beruptured. However, the provision of a number of diaphragms prevents theWater reaching the piston 9, as the temporary increase of pressure willnot be sufficient to rupture the entire serle-s. When the pressurereturns to normal, the spring 24 will return the pistonv 22 to itsinitial position, so that it will be in position for a second.operation, should a. second sudden and temporary increase of pressureoccur. I

While I have illustrated a spring, as resisting the movement of thepiston 22 in one direction and causing its movement in the oppositedirection, when the excess pressure is spent, I wish it to be understoodthat any compressible medium may bevused in place of the spring. Forinstance, the piston may work against air, or a compressible gas orfluid. In fact. in the form shown in the drawing. the piston works notonly against the action of the spring, but also against the air withinthe chamber 21, which must neces.- sarily be compressed upon the upwardmovement of the iston.

Vhat I claim is:

l. In a firing gear for depth mines, a water pressure operateddetonator, means for destroying communication between the water and thedetonator actuating mechanism, said-means being continuously accessibleto the water, and means for relieving the first mentioned means from theeect of a temporary increase in pressure.

'2. In a firing gear for depth mines, a water pressure operateddetonator, a frangible diaphragm for destroying communication betweenthe water and the detonator actuating mechanism, said diaphragm beincontinuously accessible to the Water, an

means for relieving the diaphragm from the eyiiect of a temporaryincrease of pressure.

3. In a firing gear for depth mines, a Water pressure operateddetonator, a series of frangible diaphragms for destroying communicationbetween the water and detonator actuating mechanism, said series beingcontinuously accessible to the Water, and means for relieving thediaphragms from the effect of a temporary increase of pressure.

1. In a ring gear for depth mines, a

Awater pressure operated detonator, a serles of frangible diaphragmsarranged to destroy communication between the Water' and the detonatoractuating mechanism, said series being continuously accessible to thewaterand the members of said series being successively accessible to theWater.

5 In va vfiring' gear for depth mines, a Water pressuregoperateddetonator, a series of frang'ible diaphragms, each constructed to berupturedjunder the same pressure, for

' destroying communication between the Water and the' detonatoractuating mechanism, said series being continuously accessible to thewaterand the members of said lseries being successively accessible tothe water.

6. Ina firing gear vfor depth mines, a water pressure operateddetonator, a series 1 of. frangible diaphragms, each constructed to beruptured under the same pressure, forc ldestroying communication betweenthe water and the detonator actuating mechanism,

said series being continuously. accessible to* destroying communicationbetween the Water and the detonator actuating mechanism, said seriesbemg continuously accessible to the water, a wire gauze for partiallydestroying the effect of a temporary increase of pressure lon the seriesof dlaphragms, and a yieldable-pston for further destroying the effectof said increase of pressure.

8. In a firing gear for depth mines, a water pressure operateddetonator, a series of frangible diaphragrns, each 'constructed to beruptured under the same pressure, for

destroyingcommunication between the Wa ter and the detonator actuatingmechanism, said series being continuously accessible to the water, and ayieldable piston for partially increase of pressure on the diaphragms.

destroying the effect of a temporary 'tion to the Wire gauze.

In testimony whereof I affix my sig JAMES HU]

